This invention relates to fuel-gauging systems.
The invention is more particularly, but not exclusively, concerned with fuel-gauging systems in aircraft.
Accurate fuel gauging in an aircraft plays an important part in the economic operation of the aircraft. If the quantity of fuel on an aircraft can be measured accurately and reliably it enables the minimum amount of fuel to be carried without any risk of danger. In a modern aircraft the weight of fuel can account for half the total weight of the aircraft. By reducing the amount of fuel carried, more passengers or freight can be carried. Alternatively, it can enable the aircraft to have a longer range and reduce the need for refuelling stops. Modern fuel-gauging systems can be highly accurate when operating correctly but there is always a risk that an element in the system, such as a probe or processor, will fail leading to a loss, or a reduction in accuracy, of the fuel quantity measurement in one of the tanks. It is possible to provide redundancy in the system by duplicating elements of the system so that failure of any one element will not damage the system accuracy. However, this duplication can lead to increased cost, weight and power consumption.